1. Technical Field of the Invention
The present invention relates generally to the field of image acquisition. More specifically, the present invention relates to systems and methods for obtaining and processing images of fingerprints for click detection purposes.
2. Description of Related Art
Many electronic devices, such as personal computers, laptop computers, wireless telephones and personal digital assistants (PDAs), provide a navigation mechanism for controlling a cursor or pointer on a screen. By far, the most popular navigation mechanism in PC usage is the mouse. Recently, optical mice have been developed that are able to navigate on nearly any arbitrary surface using a tracking algorithm that correlates sequential images in the direction of movement.
For example, U.S. Pat. No. 6,281,882, entitled PROXIMITY DETECTOR FOR A SEEING EYE MOUSE, which is hereby incorporated by reference in its entirety, describes an optical mouse that images the spatial features of a surface below the mouse and compares successive images to ascertain the direction and amount of movement. In addition, as described in U.S. Pat. No. 6,057,540, entitled MOUSELESS OPTICAL AND POSITION TRANSLATION TYPE SCREEN POINTER CONTROL FOR A COMPUTER SYSTEM, which is hereby incorporated by reference in its entirety, an optical finger navigation device has also been developed that detects motion of the finger and translates the finger motion into corresponding motion of the cursor or pointer on the screen.
However, the optical mice available on the market today still require the use of buttons or other electromechanical selection devices to access applications provided by the associated electronic devices. For example, typically, the user positions the screen pointer or cursor at a desired location on the screen using the navigation mechanism provided by the mouse and then “clicks” or “double clicks” to access the application highlighted or pointed to by the cursor. With the increasing trend towards miniaturization in the design of cell phones, laptop computers, personal digital assistants, electronic mice and other electronic devices, providing the space for a separate selection button on the surface of the electronic device may not be acceptable. Therefore, what is needed is an optical mechanism for detecting a click event that minimizes the amount of space required on small and/or portable electronic devices.